This disclosure relates to a gain calibration controller for a class-D amplifier system.
Class D amplifiers are used as efficient power amplifiers having relatively low power conversion. For audio amplifiers, the class D amplifier amplifies a digital audio input signal and requires for example a reconstruction filter at the output to generate the analog audio output, which is used to drive a loudspeaker. A class D audio amplifier may be implemented as an integrated circuit. A reconstruction filter may be implemented externally to the class D amplifier using a passive filter circuit constructed from inductors and capacitors. Audio class-D amplifiers are used in audio systems for cars, other automotive vehicles, and mobile devices such as laptops, mobile phones, personal digital assistants, and wearable devices, hearing aids.